Method of making panel joints



June 24, 1930. o. .1. GROEHN METHOb OF MAKING PANEL JOINTS NVNTE'Original Filed Jan. 26 1926 a a. TT RN YS- Patented June 24, 1930 UNITEDSTATES PATEN rice I OTTO J. GROEHN, OF GROSS'E POINTE PARK, MICHIGAN,ASSIGNOR TO HUDSON MOTOR CAR COMPANY, OF DETROIT, MICHIGAN, ACORPORATION OF MICHIGAN METHOD OF MAKING PANEL JOINTS Originalapplication filed January 26, 1926, Serial No. 83,960. Divided and thisapplication filed October 1, 1927, Serial No. 223,459, and in GreatBritain November 1, 1826.

This invention relates to the joining of contiguous plates or panels,and especially, although not exclusively, to the formation of reinforcedpanel joints for sheet metal automobile'bodies in accordance with theprinciples explained in a prior application for Letters Patent filedJanuary '26, 1926, Serial No. 83960, patented February 26, 1 929, No.1,703,618, of which this case is a division.

In the construction of certain types of closed automobile bodies formedfrom sheet metal panels, the. adjacent or proximate edges of contiguouspanels areformed with inturn'ed flanges which are secured together withaninterp'osed molding strip having an enlarged head at the exterior ofthe body to form a bead which covers and conceals the joint. Inaccordance with the present invention, the free edges of the moldingstrips project beyond the free edges of the panel flanges and are bentor curled thereover to form a rigid interlocking connection, theoperation of so bendingthe flanges serving also to pull the jointtogether, whereby the panels are rigidly drawn into their properrelative-positions and the head or bead of the molding strip broughtinto close engagement with the exteriorfaces of the pane-ls. In thismanner the formation of the panel joints is effected by operationsperformed wholly at the interior of the body, so that danger. ofaccidental injury to the exposed exterior surfaces of the panels isavoided, and pie-finishing of said'surfaces permitted.

7 i one of 'the'important features of the invention consists in"curling, or bending the edges-of the molding strips over the edges ofthe panel flang by an Outward edge' wise thrust, andsimultaneouslyexerting an inward reaction to said outward thrust tendingtodraw'theparts tightly into position.

Other objects of this invention will appear in the following descriptionand :appendedyclai'ms, reference being had to the accompanying drawingsforming a part of this specification, wherein-"like reference charactersdesignate corresponding parts in the several views, and wherein:

Fig. l is a longitudinal section illustrating a curling tool inoperative position to form a panel joint in accordance with theinvention.

Fig. 2 is an enlarged detail View, illustrating the beginning of thecrimping or curling operation.

Fig. 3 completion of said operation.

Fig. dis a fragmentary sectional view of, the resulting joint.

In certain types of closed automobile bodies, the enclosed body portionsthereof are constructed of sheet metal panels which are finished andreenforced by moldings at thejoints between the adjacent panel sections.As illustrated in the drawings, the panels a and b of the automobilebody are formed at the adjacent edges thereof with inturned flanges cand cl, respectively. The molding is preferably T-shaped in crosssection and may be formed by folding a strip of sheet metal upon itselfto form a curved bead or head and inwardly turned superimposed flanges gand h forming a two-ply flange which is held between the flanges c and(Z of the panels. It will be seen that the bead or head of the moldingstrip overlaps the adjacent marginal portions of the panels, engagingthe outer sur-' faces thereof and providing a means for concealing andfinishing the joint therebetween. The flanges g and lb of themoldingpreferably project a substantial distance inwardly beyond'the freeedges'of the panel flanges c and (Z, and'these edges of the molding are, inaccordance with the invention, bent or curled in opposite directions soas to embrace and. enclose the free edges of the flanges o and (Z,thereby providing. a strengthened interlocking connection between theparts. i Y I In my prior application aforesaid I have disclosed andclaimed a tool particularly adapted for the purpose of practicing [themethod constituting the subject of the present case, said tool operatingto crimp or curl the projecting edges of the superimis a similar viewillustrating'the posed molding flanges g and 71,, over the edges of thepanel flanges and d, the edges of said molding flanges being curled toform beads or rolls G and H (see Figs. 3 and 4) 'at opposite sides ofthe panel flanges. Re-

, compression spring 25 which is interposed between the piston 28 and awall of the chamber 22. Mounted on the end of the rod 24 is a curlinghammer or die member 26 which is constructed at the working face thereofto bend back or curl the free edges of the molding flanges g and h. Tueworking end of the hammer or die member 2-3 is provided with a pair oftangential arcuate surfaces or grooves 26 and 26 separated by means of atapered rib or wedge 26". As clearly seen from Fig. 2 the taperedrelativelysharp rib or wedge 26 of the die is adapt-ed to enter betweenand separate the free edges of the molding flanges g and h, as shown atm, and these edges will be curled rearwardly over the edges of the panelflanges-0 and d, forming beads G and H concentric with the curved diefaces 26 and 26.

The casing or support 20 of the tool is provided with a forwardextension27 located at one side of the path of moyeinent of the die orhammer 26. Secured, as by screws or bolts 29 to the upper face of theextension 27 is a holder or block 28 terminating atits forward end in anupward guide 30 drilled to receive a stud 31 ion ing a hook. Thesuperimposed flanges c, d, g and h of the panels and molding strip arepreviously drilled so as to provide vertically alined holes therethroughthrough which may be inserted bolts or tubularrivets-R (see Fig. 4)after the'curling operation so as to secure the parts together, The hook231 is adapted to be insertedfthrough the alined holes 0 in the moldingand panel flanges, thereby enabling the toolto be held against the workduring operation and causingthe molding flanges to be bent or cur-ledbetween the die 26 and the hook 31.

In. the presentlinstance, the piston 23 is operased'to shiftthe die orhammer 26 for wardly by pneumatic means. The cap 21 of the supportingcasing2O is connected by means of a'suitable threaded coupling. with atubular handle 34 to the rear end of which is connected a fluid orairconduit 2:35. The handle 34: is provided with. a main inlet passageorehau iber36and an outlet passage or chamber 37 separated by means of aartition 89. This )artition has a aassa 'e therethrough controlled bymeans of a suit- 'Upon completion of this operatioin'the parts ablevalve 38 provided with a stem 40 projecting tl rough a hole drilled inthe wall of the handle 34, said stein having bleeding passages 46. Theouter end of the valve stem 40 is ei'igaged by a lever ll pivoted at 42to the handle support, and by swingiug the lever 41 inwardly the valve38 will be opened against the action of thecompression spring 43interposed between ashoulder formed on the valve-and the bottom ofv achamber 44 in a removable plug 45.

In practising the present invention by the use of the tool. abovedescribeth it will be seen that the projecting stud 8l forms a hookwhich may be inserted by the operator through the verticallyalinedholesJc in the panel flanges c and .(Z. Thereupon the op eratorpresses down the handle leveiidl so as to open the valve 38 andadniit'fluid under pressure from the passage 36 into the passage 3'7,resulting in shifting the piston 23 forwardly against the actionofspring 25. The foi xvard movementof the iston will shift the hammer ordie 2fl forwardly. causing the t shaped rib or wedge 26 of the die toseparate the free edges of the molding flangesg and 72, and exert anoutward edgewise thrust thereon. The continued forward movement of thedie-26'will curl the molding strips over the panel in the manner shownin Figsfc and l. By reference tothe latter figures it will be seen thatthe holes through the panel flanges 0 and (Z. are preferably slightlylarger than the corresponding holes in themolding flanges g and 7L7 sothat when the hook 31 is engaged with the latter a certain amount ofrelative movement between the molding and the panels is permitted. There-action of the hookfll to the thrustof thec'urling die 26 exerts aninward pull upon the molding flanges,'so that as the inner edges of'thelat ter are curled over the panely flangestthe parts will be drawntightly into position.

may, if desired be furtherls'ecur'edtogether by bolts or rivets Biiiserted through; alined holes. v

Having thus described my inventiomil claimf- '"Qf I I I 1. Thehereindescribed -method o f joining the flanged edges of two panelsforplates by means of a molding strip having ahead and a flangefsaidmethodine'ludingint rposing the molding'flange between thep'anel flanges andexerting upon said"n 1olding flange opposed pressures respectively inthe directions and at the points todraw said head into close engagementwith the faces of said panels and to crimp or curl; said. molding flangeover the'free edges ofsaid panel flanges. 1 ,1. 2. The hereindescribedmethod of making a joint between panels having, .inturned flanges whichincludes provid ng a molding strip having a flange and a head, insertingthe flange of the molding strip between the panel flanges with the headengaging the outer faces of the panels, and exerting an outward edgewisethrust upon the inner edge of the molding flange to bend the same overthe edges of the panel flanges while exerting an inward pull upon themolding strip.

3. The hereindescribed method of making a joint between panels havlnginturned flanges which includes providing a molding strip having aflange and a head, inserting the flange of said molding strip betweenthe panel flanges with said head engaging the outer faces of the panels,and bending the inner edge of the molding strip flange over the edges ofthe panel flanges while exerting an inward pull upon the former.

4. The hereindescribed method of making a joint between panels havinginturned flanges which includes providing a molding strip having aflange and a head, inserting the flange of said molding strip betweenthe panel flanges with said head engaging the outer faces of the panels,and exerting opposite forces on said molding strip flange tendingrespectively to draw the same inwardly and to curl the inner edgethereof in opposite directions over the edges of the panel flanges.

5. The hereindescribed method of making a joint between panels havinginturned flanges which includes providing a molding strip having atwo-ply flange and a head, inserting the flange of said molding stripbetween the panel flanges with said head engaging the outer faces of thepanels, and curling the inner edges of the plies of the molding stripflange in opposite directions respectively over the edges of the panelflanges.

6. The hereindescribed method of making a joint between panels havinginturned flanges which includes providing a molding strip having atwo-ply flange and a head, inserting the flange of said molding stripbetween the panel flanges with said head engaging the outer faces of thepanels, and curling the inner edges of the plies of the molding stripflange in opposite directions respectively over the edges of the panelflanges, while exerting an inward pull upon said molding strip flange. V

7. The hereindescribed method of joining exterior panels in themanufacture of automobile bodies which includes interposing betweeninturned flanges on the edges of the panels the flange of a T-shapedmolding strip having its head engaging the exterior faces of the panelsand drawing the molding strip flange inwardly at the interior of thebody while securing said molding and panel flanges together.

8. The hereindescribed method of joining exterior panels in themanufacture of automobile bodies which includes interposing betweeninturned flanges on the edges of the panels the flange of a T-shapedmolding strip having its head engaging the exterior faces of the panelsand drawing the molding strip flange inwardly at the interior of thebody while bending the same to secure it to said panel flanges.

9. The hereindescribed methodof joining exterior panels in themanufacture of automobile bodies which includes interposing betweeninturned flanges on the edges of the panels the flange of a T-shapedmolding strip having its head engaging the exterior faces of the panelsand drawing the molding strip flange inwardly at the interior of thebody while curling or crimping the inner edge of said molding flangeover the inner edges of said panel flanges to secure said flangestogether.

In testimony. whereof I aflix my signature.

OTTO J. GROEHN.

